(CNN) - Maria Sharapova outlasting roadrunner Caroline Wozniacki in lengthy rallies? A few years ago it wouldn't have seemed possible.
But it happened Friday at the Australian Open as Sharapova toppled the defending champion in an absorbing three-set duel on Rod Laver Arena, 6-4 3-6 6-3.
Perhaps that should come as only a mild surprise, since the player who once described herself as a "cow on ice" moving on clay has gone on to win two French Open titles.
Even aged 31, the Russian is making adjustments and improvements.
Showing just how much better she was than Wozniacki in those lengthy exchanges, the 30th seed emerged triumphant in 17 of the 23 exchanges of nine shots or more.
She knew it, too.
"I thought it was, as usual, as expected, a physical match," Sharapova, who next faces home hope Ashleigh Barty, told reporters.
"Didn't have to be in some ways, but I felt like even in the longer rallies I did a great job of winning those. Put a lot of pressure on her. "Those are the rallies that I think many years ago that she used to win. I thought I did a great job of getting a higher percentage of wins in those."
Wozniacki refused to blame the defeat or coming out second best on the extended rallies on her rheumatoid arthritis.
"I'm okay," the third seed said. "I went out there and I was feeling fine. I feel good. I gave it everything I had today, and that was that. Definitely don't want to blame it on anything else.
"She was just a little bit better than me today. And that was really it."
Opening set key
Wozniacki rued blowing a 4-1 lead in the opening set but recovered in set two. In the third, Sharapova broke in a marathon seventh game before holding at love for 5-3. She forced a backhand error on a second match point to official oust Wozniacki.
Shoulder issues have seen Sharapova struggle with double faults and seven came off her racket. Yet she won 74% of her first serve points against one of the game's top returners and an impressive 59% behind her second delivery.
It was easily one of Sharapova's biggest wins since returning from a drug ban in 2017, equaling perhaps her victory over current world No. 1 Simona Halep in the first round of the US Open that season.
Then again it could be sweeter. Despite holding a winning record against the Dane entering the third-round clash, Wozniacki came out on top in their three highest-profile meetings. Twice at the US Open and once at the WTA Finals, all on hard courts like in Melbourne.
Sharapova's status for the year's first major was also uncertain after she retired from her lone warmup tournament this month in China with a thigh injury.
And the two will never be the best of friends.
Wozniacki criticized US Open organizers for putting Sharapova on center court in 2017 while the twice US Open finalist lost to Ekaterina Makarova on the smaller Court 17.
It famously prompted Sharapova to proclaim: "If you put me out in the parking lot of Queens in New York City, I'm happy to play there," she said. "That's not what matters to me. All that matters to me is I'm in the fourth round. I'm not sure where she is."
A pleasant handshake ensued when the match concluded after 2 1/2 hours, though Wozniacki offered a frosty reply when asked if she was on "friendly terms" with Sharapova.
"I think our terms are the same as they have always been," she said. "I think she doesn't really talk to anybody and just, you know, has her team and has her own thing. And that's that."
No extra motivation
Sharapova claimed Wozniacki's words from two years ago didn't provide her with any extra motivation entering the contest.
"I'm just really happy and proud of the way I competed today and I'm into the fourth round," said Sharapova. "So that's all that matters."
Sharapova has long resided in the US while representing Russia. Amanda Anisimova plays for the US after her parents emigrated from Russia and is hoping for grand slam success like Sharapova.
The 17-year-old became the youngest American woman since all-time great Serena Williams -- Wozniacki's good friend -- at the French Open in 1988 to make the fourth round at a major as she crushed dark horse 11th seed Aryna Sabalenka 6-3 6-2.
Meanwhile in the men's draw, pals and on-court rivals Roger Federer and Rafael Nadal are getting closer to facing off in the semifinals. Neither has surrendered a set.
Federer fended off 21-year-old American Taylor Fritz 6-2 7-5 6-2 during the day session to set a clash with another 'Next Gen' star, Stefanos Tsitsipas, before Nadal thumped 19-year-old Alex de Minaur 6-1 6-2 6-4.
The Big Four have had a way of quashing home hopes at the Australian Open, winning 19 in a row versus Australian opposition in Melbourne.
The last player to triumph? Lleyton Hewitt against a 22-year-old Nadal in 2005.
It was the third straight round the Spaniard topped a local player but he will face a Czech, and a dangerous one, in Tomas Berdych in the fourth round.
Danger for Nadal?
Berdych -- who missed the second half of 2018 with a back injury -- blew Nadal off the court at the Australian Open four years ago to snap a 17-match losing streak against the Mallorcan.
Fritz's fellow American, Frances Tiafoe followed up his upset of fifth seed Kevin Anderson by downing Italian veteran Andreas Seppi 6-7 (3-7) 6-3 4-6 6-4 6-3 for a spot in the round of 16 at a grand slam for the first time.
The 20-year-old meets Grigor Dimitrov on Sunday after the 2017 semifinalist -- being coached by Andre Agassi -- defeated Italy's Thomas Fabbiano 7-6 (7-5) 6-4 6-4.